Twitter Inc. (NYSE:TWTR): Wunderlich has initiated coverage of Twitter with a Sell rating due to valuation concerns, as the firm maintains that Twitter is a ”great company” with an “overvalued stock.” It puts a price target of $34, well under Friday’s closing price of $43.97; Wunderlich is now the third firm with a Sell rating on the microblogger’s stock.

Facebook Inc. (NASDAQ:FB): A column in The New York Times describes a somewhat bleak future in which Facebook — one of the world’s largest social media networks — is not the primary site where people go to connect, and how the company is striving to maintain its presence. Among other things, the article points to Facebook’s U.S. teen daily active user decline, recent survey data, and the rise of Snapchat, which reportedly spurned a $3 billion-plus buyout offer from Facebook.

LinkedIn Corp. (NYSE:LNKD): After taking critiques and comments for Pulse, LinkedIn has made a few adjustments and has already received a follow-up shortly after the app’s release. Pulse has been rebranded as LinkedIn Pulse and allows the user to sign in to Pulse with a LinkedIn account. The channels, influencers, and content the user follows on LinkedIn are automatically carried over onto the app, and preferences and professional interests on LinkedIn are also bridged by the app in recommending Pulse content to the user, AppAdvice reports.